This project explores the chemistry of metalloporphyrins, spin coupling phenomena, and C60, all with the goal of discovering fundamental new chemistry that underpins the molecular level understanding of biology and medicine. The bioinorganic chemistry of superstructured metalloporphyrins and fullerenes will be investigated to uncover new multi-metal and multi- electron chemistry. Iron porphyrins with chelated copper or electron reservoir substituents (e.g. C60, ferrocene) will serve as models for cytochrome oxidase. A more diverse selection of metals and ligands (e.g. 'phosphine pincer porphyrin') will allow exploitation of chemistry unique to binucleating ligands. Spin coupling phenomena will be explored, particularly to test concepts of orthogonality of magnetic orbitals. Models for peroxidase Compound I will test the difference between a-1-u and a-2-u porphyrin radical spin coupling to iron and its relationship to porphyrin ruffling. The novel concept of a Magnetochemical Series will be explored with admixed spin iron(III) porphyrins. The fundamental chemistry of C60 will be explored to establish a chemical basis for potential biomedical applications. Emphasis in all of these studies will be placed on the definitive characterization of analytically pure materials by X-ray crystallography and spectroscopic methods, on the discovery of new chemistry, and on the demonstration of relationships to the molecular level chemistry of metalloproteins, particularly hemoproteins. An understanding of this fundamental bioinorganic chemistry must underlie medical approaches to the therapy of metalloprotein disorders (thalassemias, sickle cell anemia, etc.). New ligands and their metal complexes are finding applications as anti-arthritic drugs. C60 has potential applications in photodynamic therapy and as an anti-viral agent.